When the UK leaves the EU, uncontrolled EU immigration is expected to end. Meanwhile customs declarations are expected to increase dramatically.

This will be no mean challenge. Currently, detailed border checks are done on 12 million visitors to the UK. The end of EU free movement can be expected to increase this number by 25.5 million to total some 37.5 million visitors. Customs declarations are currently made by 141,000 traders. This can be expected to rise by 180,000 to a total of 320,000 traders. Meanwhile it is expected that the number of customs declarations would go from 60 million a year to over 300 million.

These challenges would be additional to the problem of so many different parts of Government having border responsibilities. There are 38 organisations and 57 different systems operating at the border. These organisations report to a wide array of different Departments and Secretaries of State. That inevitably can lead to confusion, muddle and duplication of effort.

As we leave the EU it's clear there is an urgent need to invest, professionalise and streamline Government activities at the border. This is not just to help ensure that Britain can cope with Brexit. It will also ensure a greater priority on the collection of border taxes. For no longer will Border Force officers report to a Home Secretary with primary responsibility for immigration rather than collecting border taxes – a new single department would be led by a Secretary of State equally concerned about collecting cash. There are concerns that the collection of border taxes has not been as complete as might be the case, to the tune of some billions of pounds. A new department would be in a stronger position to focus on ensuring taxes due are paid – meaning investment would more than pay for itself.

A single department would be in a stronger position to streamline the current confusing array of different systems. It would be better able to adopt the most modern systems and embrace digital borders. This matters to ensure frictionless borders for customs and trade. Yet it also matters to boost security and counter illegal immigration. For example, using information systems effectively it would be easier to prevent criminals entering the UK and to find visa overstayers swiftly, helping them back to their home nations.

One department reducing duplication of effort would cost less due to efficiencies. It would be able to focus on investing in modern digital systems – increasing security and enabling the UK's borders to cope with the greater checks that Brexit is expected to require. A more efficient border would also lead to an increase in economic growth and reduce costs to British business by more than £2 billion a year.

Investment in the UK border has flatlined over the past few years. Too often it seems as if the border is seen as a problem to be patched-up rather than an asset to be fully modernised. Investment now in state-of-the-art systems will be repaid as we recoup more in border taxes. And, with the threat of returning ISIS fighters, it's more important than ever that our border is policed by highly-trained professionals. To keep our nation secure, border officers must have access to the latest technology and biometrics, as well as better data sharing.

Singapore has taken a "one government at the border" approach and is now a world leader in border management and technology. We should be ambitious and seek to build a modern border system ready to boost British trade across the globe.

This is why there is an urgent need for one government at the border, with the establishment of a Department for Security and Border Taxes.